The search for the electrically-excited organic laser has a long history. These papers report on the first successful observation of coherent emission from organic semiconductors using electrical excitation (or electrical pumping). The gain medium in these interferometric emitters is the laser dye coumarin 545 tetramethyl. The coherent emission is generated in a miniature, sub micrometer, resonator. The emission beam is nearly diffraction limited and the spectral linewidth has been determined, using interferometric means, to be ~ 11 nm which approximates the linewidths available from broadband dye lasers. Thus, the spatial and spectral coherence characterictics, from these pulsed interferometric emitters, are indistinguishable from broad-band dye laser emission. Note: the organic semiconductors used in these experiments are tandem organic light-emitting diodes also known as tandem oleds.
F. J. Duarte, Coherent electrically-excited organic semiconductors: visibility of interferograms and emission linewidth, Opt. Lett. 32, 412-414 (2007).